WAVERLY, Iowa – Residents in Waverly will apparently escape the high water on the Cedar River with just minor damage.

The river crested just before 5:00 o'clock Wednesday morning at 13.13 feet. That's just a foot or so above flood stage and is considered a mild to moderate flood event.

City officials say water remains over some low-lying streets on the southeast side of that Bremer County community, but there is access via one older bridge. Currently, police are only allowing residents over the bridge and into the area. Once the water drops low enough, the city will open other streets and close the bridge for a safety inspection.

City administrator Phil Jones said at least part of the credit involved in avoiding major flooding issues probably has to go to an inflatable dam on the Cedar River that opened in November 2011.

Currently the dam is not visible in the river because it is deflated and below the level of the water. In normal times, it's inflated and intended to keep a higher water level upstream for recreation. But when the water rises, the dam can automatically deflate to allow water to pass more quickly and without backing up.

The Schroeder family has lived along the river upstream for about 20 years. And they know the ups and downs of water levels. They were pleasantly surprised by how well the inflatable system worked with this flood.

Richard Schroeder said "at this flood level, there's no damage at all. In the worst flooding, it should help tremendously and that's the difference between a little bit of cleanup and tearing everything out again like in 2008."

Federal dollars helped pay for the majority of the $4.3- million dollar project. It replaced a traditional "low head" concrete dam that doesn't have the ability to raise or lower to adjust to water levels.

Mike Cherry, Waverly city engineer, said the difference was dramatic. With the old low head dam that was torn out, the water from a flood this size would have forced the Cedar River out of its banks and into some streets near the downtown. And the city never felt the need to take normal flood precautions.

"It's making a huge difference," Cherry said adding "without it we would have established sandbagging stations and would have had to work to protect the nearby school and church."

Jones said the inflatable dam, by itself, probably dropped river levels five or six feet lower than the old dam in the downtown area. And because the dam adjusts to river levels automatically, city workers didn't have to frantically make changes with the flood forecast.

Jones said the inflatable dam could eventually help residents get lower flood insurance rates. With the dam in place, FEMA is redrawing the 100-year flood plain in Waverly. As many as 400 to 500 homes may eventually move to a lesser flood risk category and qualify for cheaper rates.